新手请教个正则表达式的问题 - V2EX

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This topic created in 3162 days ago, the information mentioned may be changed or developed.

print(re.findall("(as)|3","3as")) 为什么执行结果是 ['', 'as'] 怎么会出现一个空字符串呢,谢谢

1 replies

frostming

Mar 20, 2018

1

1

https://docs.python.org/2/library/re.html#re.findall

If one or more groups are present in the pattern, return a list of groups;

如果有分组则返回分组，你这里有分组，但‘ 3 ’没有分组，所以匹配到了 3，仍返回了一个空

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